1. Field of the Invention
The present invention relates to a focus adjustment unit and a camera system that set a focus detection area within an imaging area and performs focus adjustment based on a focus detection signal in the focus detection area.
2. Description of Related Art
AF (Auto Focus) is known generally, which brings a subject into focus by adjusting the position of a focusing lens using an image signal from an image sensor at the time of imaging. For example, focus detection is performed on an AF area fixed within the imaging area and the position of the focusing lens is adjusted based on this focus detection information.
In such a focus adjustment method, the size of a subject image changes in accordance with zooming of a zoom lens and the subject image corresponding to the AF area changes, and therefore, there may occur a problem that focus adjustment accuracy is decreased. To address such a problem, in the lens control unit disclosed in Japanese Unexamined Patent Publication No. 2005-025118, the AF area is scaled in accordance with an image magnification change due to zooming so that the AF area corresponding to the subject is fixed apparently at all the times.